20852509 has 2 divisors, whose sum is σ = 20852510. Its totient is φ = 20852508.

The previous prime is 20852501. The next prime is 20852521. The reversal of 20852509 is 90525802.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14273284 + 6579225 = 3778^2 + 2565^2 .

It is a cyclic number.

It is not a de Polignac number, because 20852509 - 2³ = 20852501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20852501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10426254 + 10426255.

It is an arithmetic number, because the mean of its divisors is an integer number (10426255).

Almost surely, 2^20852509 is an apocalyptic number.

It is an amenable number.

20852509 is a deficient number, since it is larger than the sum of its proper divisors (1).

20852509 is an equidigital number, since it uses as much as digits as its factorization.

20852509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 20852509 is about 4566.4547517741. The cubic root of 20852509 is about 275.2450003945.

The spelling of 20852509 in words is "twenty million, eight hundred fifty-two thousand, five hundred nine".